Benchmark: replaceChildren vs documentFragment [2]

HTML Preparation code:

<div id="container"></div>

Script Preparation code:

var elements = [document.createElement('div'), document.createElement('div')];
var container = document.getElementById('container');

Tests:

replaceChildren
container.replaceChildren(...elements);
append documentFragment
var newChildren = document.createDocumentFragment(); newChildren.append(...elements); container.replaceChildren(newChildren);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replaceChildren
append documentFragment

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore what's happening in this specific benchmark.

**Benchmark Overview**

The benchmark is designed to compare two approaches: `replaceChildren` and appending a `documentFragment`. The goal is to determine which approach is faster for replacing child nodes in an HTML container.

**Script Preparation Code**

The script preparation code creates two elements (`div`) and assigns them to an array called `elements`. It then retrieves a container element with the ID "container" using `document.getElementById`.

**Html Preparation Code**

The html preparation code creates a basic HTML structure with a single container element that doesn't have any children.

**Benchmark Definition Json**

The benchmark definition json contains two test cases:

1. `replaceChildren`: This test case calls the `replaceChildren` method on the container element, passing in the entire array of elements.
2. `append documentFragment`: This test case creates a new `documentFragment`, appends all the elements to it using `append()`, and then replaces the children of the container element with the new fragment.

**Options Compared**

The benchmark is comparing two options:

1. **replaceChildren**: This method replaces the child nodes of the container element with a new set of nodes.
2. **Applying a documentFragment**: Instead of replacing the existing child nodes, this approach creates a new `documentFragment`, appends all the elements to it, and then replaces the children of the container element with the new fragment.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

**replaceChildren**

Pros:

* This is a native method that has been around for a long time.
* It might be optimized by the browser for performance.

Cons:

* This method can lead to slower rendering because it replaces all child nodes at once, which can cause unnecessary reflows or repaints.

**Applying a documentFragment**

Pros:

* This approach is generally faster because it avoids replacing existing child nodes and instead creates a new fragment that contains all the elements.
* It's also more efficient in terms of memory usage because it doesn't require storing temporary arrays of child nodes.

Cons:

* This method requires creating a new `documentFragment` object, which can be slightly slower than calling `replaceChildren`.
* Some browsers might optimize `append()` to being faster than `replaceChildren`, but this is not always the case.

**Other Considerations**

One important consideration is that both approaches have different memory usage implications. The `replaceChildren` method can lead to a larger memory footprint because it stores temporary arrays of child nodes, while applying a `documentFragment` reduces memory usage by reusing the fragment instead of creating new arrays.

Another consideration is the rendering performance of each approach. Replacing existing child nodes using `replaceChildren` can cause slower rendering times due to unnecessary reflows or repaints, while applying a `documentFragment` avoids these issues because it creates a new fragment that contains all the elements without modifying the container's children.

**Library and Special JS Feature**

There is no library involved in this benchmark. However, `documentFragment` is a built-in JavaScript feature that allows you to create a temporary container for DOM nodes before replacing them with new content.

I hope this explanation helps you understand what's happening in this specific benchmark!

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
replaceChildren	1179047.9 Ops/sec
append documentFragment	746938.8 Ops/sec

Related benchmarks:

replaceChildren vs documentFragment [2] (version: 0)

Comparing performance of: replaceChildren vs append documentFragment

Created: one year ago by: Guest

Jump to the latest result

replaceChildren

append documentFragment

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):